It's been occupied for the last several years by up to 5 adult female RBBS, which spend the colder months together there. "Denning " is a good description, I call it a "brumation site" for want of a better description. Not all the females are visible everyday, but at least two are regularly seen when weather permits. From as early as late August (26th) , the females begin to disperse along the creekline and aren't seen again back at the site until mid May. I am able to recognise the same individuals every year (through various visual references) which I've really come to look forward to
! Occasionally, if I'm really fortunate, I've found large males "wrestling" not far from the den site, which are totally oblivious to my approach. I once sat and watched for 20 minutes, until one was persued across the creek by the other. Something new I've noticed this year is a local resident EB occupying the same site over Summer, obviously when "my girls" are elswhere.